Trichomycterus pantherinus, Aline R. Alencar & Wilson J. E. M. Costa, 2004

Aline R. Alencar & Wilson J. E. M. Costa, 2004, Description of two new species of the catfish genus Trichomycterus from southeastern Brazil (Siluriformes: Trichomycteridae)., Zootaxa 744, pp. 1-8 : 2-5

Trichomycterus pantherinus new species

(Fig.1)

Holotype. UFRJ 6001 , 55.3 mm SL; Brazil: Estado do Espírito Santo: Municipio de Santa Leopoldina, below waterfall near Fazenda Sete Quedas, Rio da Prata, Rio Santa Maria da Vitoria basin , 20°03’15.9”S 40°32’20.5”W, altitude 377 m; W. J. E. M. Costa, B. B. Costa and C. P. Bove, 2 January 2003.

Paratypes. MCP 35029 , 6 ex., 37.0-45.9 mm SL; UFRJ 5659 , 22 ex., 32.9-69.9 mm SL; UFRJ 5660 , 6 ex. (c&s), 40.6-48.5 mm SL; all collected with holotype.

Diagnosis: Similar to T. alternatus (Eigenmann) , T. longibarbatus and T. caudofasciatus , and distinguished from other congeners by the combination of the following features: 7-8 pectoral-fin rays, long filamentous first pectoral-fin ray (about 50-70 % pectoral-fin length), 10-20 opercular odontodes, 30-52 interopercular odontodes, opercular patch of odontodes wide, and 6-7 branchiostegal rays. It differs from T. alternatus , T. longibarbatus and T. caudofasciatus by the absence of anteriormost section of infraorbital canal (vs. presence) and having 7 pectoral-fin rays (vs. 8 rays). It differs from all other species of the genus from the Brazilian Shield river basins by a unique color pattern, consisting of a light orangish yellow flank with dark brown to black rounded spots irregularly distributed.

Description: Morphometric data for holotype and paratypes given in Table 1. Body moderately deep, subcylindrical on anterior portion, compressed on caudal peduncle. Dorsal profile slightly convex between snout and end of dorsal-fin base, straight to slightly convex on caudal peduncle. Ventral profile straight to slightly convex between lower jaw and end of anal-fin base, straight on caudal peduncle. Greatest body depth in vertical immediately in front of pelvic-fin origin. Skin papillae minute. Urogenital papilla spherical, at vertical just anterior to dorsal-fin base.

Dorsal and anal fins approximately triangular. Dorsal-fin origin at vertical through centrum of 18th or 19th vertebrae. Anal-fin origin at vertical through base of 8th or 9th dorsal-fin ray and through centrum of 22nd or 23rd vertebra. Pectoral fin about triangular, lateral and posterior edges slightly convex. First pectoral-fin ray terminating in long filament, about 50 % of pectoral-fin length. Pelvic fin shorter than anal fin, covering urogenital pore, tip not reaching anal-fin, in vertical through base of 2nd unbranched dorsal-fin ray; pelvic-fin bases separated by interspace; pelvic-fin origin in vertical through centrum of 15th or 16th vertebra. Caudal fin subtruncate. Dorsal-fin rays 11-12; anal-fin rays 9-10; pectoral-fin rays 7; pelvic-fin rays 5; caudal-fin principal rays 13, dorsal procurrent rays 18-19, ventral procurrent rays 14-15. Total vertebrae 36-37; pleural ribs 11-13. Upper hypural plates separated, both approximately equal in width; single lower hypural plate and parahypural completely fused.

Head trapezoidal in dorsal view. Snout blunt. Mouth subventral. Maxilla slightly shorter than premaxilla. Teeth cylindrical, tips slightly pointed. Eye at middle of head. Nasal, maxillary and rictal barbels well developed. Tip of nasal barbel reaching posterior edge of opercular patch of odontodes. Tip of maxillary barbel reaching pectoral-fin base. Tip of rictal barbel reaching posterior portion of interopercular patch of odontodes. Seven branchiostegal rays. Interopercular odontodes 36-40; opercular patch of odontodes wide, with 12-20 odontodes; odontodes conical, opercular odontodes wider than interopercular odontodes; opercular odontodes arranged vertically.

Supraorbital canal continuous, with three pores; first pore in transverse line through anterior nostril, second in transverse line just posterior to posterior nostril, third supraorbital pore paired, each pore closer to symmetrical pore than to orbit in transverse line just posterior to orbit. Infraorbital divided into two sections, each with two pores, anteriormost section absent; first infraorbital pore in transverse line through anterior nostril, second in transverse line just anterior to posterior nostril, third and fourth posterior to orbit. Preopercular canal with one pore, in vertical through anterior margin of opercular patch of odontodes. Lateral line of body short, with three pores, posteriormost pore in vertical just posterior to pectoral-fin base.

Coloration: Side of body light orangish yellow, sometimes pale greenish yellow, with small dark brown to black rounded spots irregularly distributed, sometimes coalesced to form lateral stripe on anterior portion of lateral midline, sometimes forming transverse bars on dorsum; venter white. Side of head orangish yellow with dark brown spots; dark chromatophores concentrated on preopercular region; opercular and interopercular patches of odontodes light yellow. Dorsal surface of head brown, with dark brown blotch on middle of dorsal surface of head in vertical through opercle, sometimes Y-shaped light area uniting anterior dorsal midline and anterior nares; dark chromatophores concentrated around nostrils; barbels dark gray; ventral surface of head white. Iris yellow. Dorsal fin pale yellow with small dark brown spots on basal portion. Caudal fin pale orange with small dark brown spots on basal portion. Anal and pelvic fins pale yellow. Pectoral fin yellow, with dark brown spot on basal region; pectoral filament white.

Distribution: Known only from the type locality, Rio da Prata, Rio Santa Maria da Vitória basin, Serra dos Polacos, southeastern Brazil.

Habitat notes: This new species was collected in a clear water stream below a waterfall. All specimens were found in shallow waters (about 30-40 cm deep), under marginal vegetation. In these places the bottom was composed of gravel and the current reached high velocity.

Etymology: From the Latin pantherinus (pertaining to the panther), an allusion to the color pattern of the new species.